Justus Justus - 2 months ago 11
Java Question

Java autentication of Drupal passwords

I try to mimic the way Drupal 7 is checking for a correct password in Java.
Found some code as a guideline here: https://github.com/CraftFire/AuthDB-Legacy/blob/master/src/main/java/com/authdb/scripts/cms/Drupal.java and extracted the code i needed.

The thing is however that when i give the password and the hashed version (in order to extract the salt and amount of iterations needed), i get different results.

The passwords are generated using the Drupal password-hash script
resulting in:

Expected value = $S$DxVn7wubSRzoK9X2pkGx4njeDRkLEgdqPphc2ZXkkb8Viy8JEGf3
Calculated value = $S$DxVn7wubSpQ1CpUnBZZHNqIXMp2XMVZHMYBqAs24NsUHMY7HBkYn

Expected value = $S$DOASeKfBzZoqgSRl/mBnK06GlLESyMHZ81jyUueEBiCrkkxxArpR
Calculated value = $S$DOASeKfBzs.XMVZ1NkYXNmIqMpEHAoEaMYJ1NmUHCZJaBZFnAZFX


Anyone able to help me / tell me what i'm doing wrong here?
Thanks.

Code:

import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

class test {

public static void main(String args[]) {
// Passwords and hashes generated by Drupal.
checkPassword("test" , "$S$DxVn7wubSRzoK9X2pkGx4njeDRkLEgdqPphc2ZXkkb8Viy8JEGf3");
checkPassword("barbaz", "$S$DOASeKfBzZoqgSRl/mBnK06GlLESyMHZ81jyUueEBiCrkkxxArpR");
}

private static String itoa64 = "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
private static final int DRUPAL_HASH_LENGTH = 55;
private static int password_get_count_log2(String setting) { return itoa64.indexOf(setting.charAt(3)); }

/**
* Note: taken from the default Drupal 7 password algorithm
* @param candidate
* the clear text password
* @param saltedEncryptedPassword
* the salted encrypted password string to check => NEEDS TO BE THE DEFAULT DRUPAL 7 PASSWORD HASH.
* @return true if the candidate matches, false otherwise.
*/
public static boolean checkPassword(String candidate, String saltedEncryptedPassword) {
if (candidate == null) {
return false;
}
if (saltedEncryptedPassword == null) {
return false;
}

String hash = password_crypt(candidate, saltedEncryptedPassword);
System.out.println("Tested value = " + saltedEncryptedPassword);
System.out.println("Calced value = " + hash);

return hash == saltedEncryptedPassword;
}

public static String SHA512(String text) {
byte[] sha1hash = new byte[40];
try {
MessageDigest md = MessageDigest.getInstance("SHA-512");
md.update(text.getBytes("UTF-8"), 0, text.length());
sha1hash = md.digest();
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
return convertToHex(sha1hash);
}

private static String convertToHex(byte[] data) {
StringBuffer buf = new StringBuffer();
for (int i = 0; i < data.length; i++) {
int halfbyte = (data[i] >>> 4) & 0x0F;
int two_halfs = 0;
do {
if ((0 <= halfbyte) && (halfbyte <= 9))
buf.append((char) ('0' + halfbyte));
else
buf.append((char) ('a' + (halfbyte - 10)));
halfbyte = data[i] & 0x0F;
}
while(two_halfs++ < 1);
}
return buf.toString();
}

private static String password_crypt(String password, String setting) {
// The first 12 characters of an existing hash are its setting string.
setting = setting.substring(0, 12);
int count_log2 = password_get_count_log2(setting);

String salt = setting.substring(4, 12);
// Hashes must have an 8 character salt.
if (salt.length() != 8) {
return null;
}

// Convert the base 2 logarithm into an integer.
int count = 1 << count_log2;

String hash;
try {
hash = SHA512(salt + password);
do {
hash = SHA512(hash + password);
} while (--count >= 0);
} catch(Exception e) {
return null;
}

int len = hash.length();
String output = setting + password_base64_encode(hash, len);
return (output.length() > 0) ? output.substring(0, DRUPAL_HASH_LENGTH) : null;
}

private static String password_base64_encode(String input, int count) {
StringBuffer output = new StringBuffer();
int i = 0, value;
do {
value = input.charAt(i++);
output.append(itoa64.charAt(value & 0x3f));
if (i < count) {
value |= input.charAt(i) << 8;
}
output.append(itoa64.charAt((value >> 6) & 0x3f));
if (i++ >= count) {
break;
}
if (i < count) {
value |= input.charAt(i) << 16;
}
output.append(itoa64.charAt((value >> 12) & 0x3f));
if (i++ >= count) {
break;
}
output.append(itoa64.charAt((value >> 18) & 0x3f));
} while (i < count);
return output.toString();
}

}


--
ps.
One thing i already see is the following:
Consider these functions:

public String convertToHex(byte[] data) {
StringBuffer buf = new StringBuffer();
for (int i = 0; i < data.length; i++) {
int halfbyte = (data[i] >>> 4) & 0x0F;
int two_halfs = 0;
do {
if ((0 <= halfbyte) && (halfbyte <= 9))
buf.append((char) ('0' + halfbyte));
else
buf.append((char) ('a' + (halfbyte - 10)));
halfbyte = data[i] & 0x0F;
}
while(two_halfs++ < 1);
}
return buf.toString();
}


and

public String convertToHex(byte [] raw) {
StringBuilder hex = new StringBuilder(2 * raw.length);
for (final byte b : raw) {
int hiVal = (b & 0xF0) >> 4;
int loVal = b & 0x0F;
hex.append((char) ('0' + (hiVal + (hiVal / 10 * 7))));
hex.append((char) ('0' + (loVal + (loVal / 10 * 7))));
}
return hex.toString();
}


The first function returns the string as a lowercase, the second is returned as higher case string. Don't know which to use, both are returning different results in the end, but neither is satisfying.

-Edit-

Almost there???...

Came a step further, changes the question a bit...
In Drupal the following function is used:

$hash = hash($algo, $salt . $password, TRUE);


that returns

'���Y�emb
ӈ3����4��q����h�osab��V�!IS�uC�*[�


As you see, we do not need the hex version, since you get a total different hash back...
So i altered the code in java:

public byte[] SHA512(String text) {
byte[] sha1hash = new byte[50];
try {
MessageDigest md = MessageDigest.getInstance("SHA-512");
md.update(text.getBytes("UTF-8"), 0, text.length());
sha1hash = md.digest();
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
return sha1hash;
}

--snip--
hash = new String(SHA512(salt + password));
System.out.println(hash);


that returns:

'���Y�emb
ӈ3����4��q���h�osab��V�!IS�uC�*[�


As you see thats ALMOST the same....

php: ӈ3����4��q����h�osab��V�!IS�uC�*[�
java: ӈ3����4��q���h�osab��V�!IS�uC�*[�


Anyone got a clue how to fix that last part?
The form new String(SHA512(salt + password,'Whatevercodec')); did not help me...
Thanks!

Answer

I suggest that you do something like this:

import java.security.NoSuchAlgorithmException;

public class hash {

private static final int DRUPAL_HASH_LENGTH = 55;

private static String _password_itoa64() {
    return "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
}

public static void main(String args[]) throws Exception {
    // Passwords and hashes generated by Drupal.
    checkPassword("adrian", "$S$DNbBTrkalsPChLsqajHUQS18pBBxzSTQW0310SzivTy7HDQ.zgyG");
    checkPassword("test"  , "$S$DxVn7wubSRzoK9X2pkGx4njeDRkLEgdqPphc2ZXkkb8Viy8JEGf3");
    checkPassword("barbaz", "$S$DOASeKfBzZoqgSRl/mBnK06GlLESyMHZ81jyUueEBiCrkkxxArpR");
}


private static int password_get_count_log2(String setting) {
    return _password_itoa64().indexOf(setting.charAt(3));
}


private static byte[] sha512(String input) {
    try {
        return java.security.MessageDigest.getInstance("SHA-512").digest(input.getBytes());
    } catch (NoSuchAlgorithmException ex) {
        ex.printStackTrace();
    }
    return new byte[0];
}

private static byte[] sha512(byte[] input) {
    try {
        return java.security.MessageDigest.getInstance("SHA-512").digest(input);
    } catch (NoSuchAlgorithmException ex) {
        ex.printStackTrace();
    }
    return new byte[0];
}

/**
 * Note: taken from the default Drupal 7 password algorithm
 *
 * @param candidate               the clear text password
 * @param saltedEncryptedPassword the salted encrypted password string to check => NEEDS TO BE THE DEFAULT DRUPAL 7 PASSWORD HASH.
 * @return true if the candidate matches, false otherwise.
 */
public static boolean checkPassword(String candidate, String saltedEncryptedPassword) throws Exception {
    if (candidate == null || saltedEncryptedPassword == null) {
        return false;
    }

    String hash = password_crypt(candidate, saltedEncryptedPassword);
    System.out.println("Expected value = " + saltedEncryptedPassword);
    System.out.println("Calced   value = " + hash);
    System.out.println("Result Good?   = " + saltedEncryptedPassword.equalsIgnoreCase(hash));


    return saltedEncryptedPassword.equalsIgnoreCase(hash);
}


private static String password_crypt(String password, String passwordHash) throws Exception {
    // The first 12 characters of an existing hash are its setting string.
    passwordHash = passwordHash.substring(0, 12);
    int count_log2 = password_get_count_log2(passwordHash);
    String salt = passwordHash.substring(4, 12);
    // Hashes must have an 8 character salt.
    if (salt.length() != 8) {
        return null;
    }

    int count = 1 << count_log2;


    byte[] hash;
    try {
        hash = sha512(salt.concat(password));

        do {
            hash = sha512(joinBytes(hash, password.getBytes("UTF-8")));
        } while (--count > 0);
    } catch (Exception e) {
        System.out.println("error " + e.toString());
        return null;
    }

    String output = passwordHash + _password_base64_encode(hash, hash.length);
    return (output.length() > 0) ? output.substring(0, DRUPAL_HASH_LENGTH) : null;
}

private static byte[] joinBytes(byte[] a, byte[] b) {
    byte[] combined = new byte[a.length + b.length];

    System.arraycopy(a, 0, combined, 0, a.length);
    System.arraycopy(b, 0, combined, a.length, b.length);
    return combined;
}



private static String _password_base64_encode(byte[] input, int count) throws Exception {

    StringBuffer output = new StringBuffer();
    int i = 0;
    CharSequence itoa64 = _password_itoa64();
    do {
        long value = SignedByteToUnsignedLong(input[i++]);

        output.append(itoa64.charAt((int) value & 0x3f));
        if (i < count) {
            value |= SignedByteToUnsignedLong(input[i]) << 8;
        }
        output.append(itoa64.charAt((int) (value >> 6) & 0x3f));
        if (i++ >= count) {
            break;
        }
        if (i < count) {
            value |=  SignedByteToUnsignedLong(input[i]) << 16;
        }

        output.append(itoa64.charAt((int) (value >> 12) & 0x3f));
        if (i++ >= count) {
            break;
        }
        output.append(itoa64.charAt((int) (value >> 18) & 0x3f));
    } while (i < count);

    return output.toString();
}


public static long SignedByteToUnsignedLong(byte b) {
    return b & 0xFF;
}

}
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